I have a 1999 M9000 with about 1800 hrs. I am the second owner and the previous owner told me during cold weather, the engine would shut off if the oil pressure light stayed on too long. Sure enough, tractor will start fine , run for a bit, 20 seconds maybe and shut down if the oil pressure light is still on. On the second start, the OP light goes off and tractor runs fine. Water separator & fuel filter has been changed, diesel supplement added. Dealer service Mgr says no connection between oil pressure light and shut off. Is this truly a safety precaution or do I have something going bad. Thanks